Testing of BGA and other CSP packages using probing techniques

ABSTRACT

A method and apparatus for handling small semiconductor devices in the testing of these devices. Multiple devices are mounted within a device strip carrier and are positioned in the testing position. This positioning of the device strip carriers is performed using device strip carrier alignment tools; the device strip carrier can readily be repositioned with respect to the test head/probe card for testing of multiple devices contained within the device strip carrier.

This is a division of patent application Ser. No. 09/252,629, filingdate Feb. 18, 1999, Testing Of Bga And Other Csp Packages Using ProbingTechniques, now U.S. Pat. No. 6,404,212, assigned to the same assigneeas the present invention.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The invention relates to the fabrication of semiconductor IntegratedCircuits, and more specifically to a method of final testing of BallGrid Array (BGA) and Chip Scale Packaging (CSP) Integrated Circuitchips.

(2) Description of the Prior Art

A Ball Grid Array (BGA) is an array of solderable balls placed on a chipcarrier. The balls contact a printed circuit board in an arrayconfiguration where, after reheat, the balls connect the chip to theprinted circuit board. BGA's are known with 40, 50 and 60 mils. spacingsin regular and staggered array patterns.

In order to test a BGA device, the contactor elements of the BGA deviceare inserted into a contactor plate having a plurality of sockets. Thecontactor plate is coupled to a Device Under Test (DUT) board, which iscoupled to a testing machine. The DUT board is in essence a printedcircuit board that completes electrical connections between the BGAcontactor elements via the contactor plate and the tester. In order totest the BGA device, the tester sends signals to and receives signalsfrom the BGA device via the electrical conductor paths provided by thecontactor plate and the DUT board.

At present the final testing of semiconductor Integrated Circuits isperformed using Integrated Circuit Handler apparatus whereby each of theIC packages is handled as an individual unit and is advanced to the testsocket of the DUT by either gravity feed or by using pick and placemethods.

U.S. Pat. No. 5,570,033 (Staab) shows a spring probe BGA contactor.

U.S. Pat. No. 5,721,496 (Farnworth et al.) discloses a method fortesting unpackaged dies.

U.S. Pat. No. 5,729,896 (Dalal et al.) displays a Flip chip carrier.

U.S. Pat. No. 5,574,668 (Beaty) teaches a method for measuring BGAdevices.

SUMMARY OF THE INVENTION

The present invention teaches an apparatus and method for testingintegrated semiconductor circuits by means of device strip testing usingprobing techniques.

Using the current practice of handling integrated circuit packages on anindividual basis presents problems of difficulty of handling theever-decreasing size of the packages. Shrinking integrated circuitpackages further aggravate the problems of increased tooling costs andincreased lead time for test kit modifications due to the smaller ICpackages and to the higher demands posed by the more accurate tolerancesrequired for the smaller IC packages.

The present invention addresses these problems by using a new method oftesting the IC packages. The need to handle IC packages on an individualbasis is eliminated by using IC probing techniques applied by means of amodified probing apparatus. The individual testing of each semiconductordevice will in this manner be replaced by Device Strip Testing whichwill be performed by the modified probing apparatus. The presentinvention does not require new or special tooling with the exception ofthe probe card which is unique for and adapted to each type of ICpackage. The time required to handle and test the integrated circuitswill as a consequence be sharply reduced.

A plurality of individual BGA/CSP chips will be mounted on a strip, thisstrip will be referred to as the device strip. The device strip in turnwill be mounted on an adhesive tape attached to a rigid platform (knownas wafer ring) for handling of the device strip before, during and afterdevice testing operations. This platform will be referred to as thedevice strip carrier. The number of BGA/CSP chips that can be mounted onone device strip is determined by the length of the device strip and bya particular package size. A device strip carrier that, for instance,can handle a device strip with a length of 8 inches (this length can beincreased or decreased to fit into a 12-inch wafer frame) is referred toas a 12-inch device strip carrier.

The device strip is typically made of bismaleimide triazene (BT)substrate material. The BGA/CSP devices are strip mounted to the stripcarrier using adhesive tape, this operation is a machine operation. Thestrip to strip carrier mount accuracy in the X and Y-directions is ±0.05mm, the theta rotation accuracy is ±0.5 degrees.

A device strip is further subdivided into sites; each site contains amultiplicity of BGA/CSP chips or devices.

To summarize the above:

a multiplicity of BGA/CSP devices forms a site

a multiplicity of sites forms a device strip

one or more device strips may be mounted on a device strip carrier.

the device strip carrier provides the means for handling the BGA/CSPdevices in the new device probing apparatus.

The new probing apparatus of the present invention has the followingperformance characteristics:

1) be capable of handling 12 inch device strip carriers while theprobing apparatus can easily be modified to handle either larger orsmaller device strip carriers

2) use cassettes that serve as the means for handling a plurality ofdevice strip carriers in the environment of the new probing apparatus

3) use a loading/unloading arm for loading/unloading device stripcarriers into and from device strip carrier cassettes

4) provide alignment of the Device Under Test (DUT)

5) be equipped with a loader/unloading transfer arm that transfers thedevice strip carrier form the loading/unloading arm to the devicetesting platform (the main chuck and heater table, see following item)and that can handle 12 inch device strip carriers and that can be easilymodified to handle either larger or smaller device strip carriers

6) be equipped with a main chuck and heater table that secures the DUTduring testing and that can handle 12 inch device strip carriers andthat can easily be modified to handle either larger or smaller devicestrip carriers

7) provide two types of stepping capabilities, that is device to devicewithin a site and site to site within a device strip.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1a and 1 b show a plan overview of a BGA/CSP device strip with itssupporting device strip carrier.

FIG. 2 shows an isometric view of the probe handler.

FIG. 3 shows a plan view of the main chuck and heater table.

FIG. 4 shows a detailed plan view of the probe handler.

FIG. 5 shows a plan view of the probe handler with the device stripcarrier cassette, the loading/unloading arm and the loading/unloadingtransfer arm and the main chuck/heater table.

FIGS. 6a and 6 b show two test probe pins.

FIGS. 7a through 7 c show cross sectional views and plan views of theBGA/CSP testing apparatus.

FIGS. 8a, 8 b and 8 c show cross sections of micro-probing apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now more specifically to FIG. 1a, there is shown a plan overviewof a BGA/CSP device strip carrier 14 on top of which a device strip 12of BGA/CSP devices has been positioned. The present diameter of thisBGA/CSF strip carrier is 12 inches. The BGA/CSP device strip carrier 14will be used as the base for handling the BGA/CSP devices in the deviceprober. One site within the device strip 12 is indicated by 16, thedevice strip 12 contains a multiplicity of device sites. Each devicesite 16 within the device strip contains a multiplicity of BGA/CSPdevices as further detailed in FIG. 1b. The presently envisioned lengthof the device strip 12 is 8 inches (typically 190 mm), this length canhowever readily be reduced or extended to 10 inches or any other sizedependent on particular device strip and device testing applications.The thickness of the carrier plate 14 should typically not exceed thethickness of the BGA/CSP device of 1.4 mm. The device strip 12 is keptin position within the device strip carrier 14 by means of a surface 15of sticking or adhering film. Cutouts 17 provided in the circumferenceof the BGA device strip carrier 14 serve to guide the insertion of theBGA device strip carrier 14 into the BGA probe handler, this will bediscussed at a later time under FIG. 2.

FIG. 1b shows a plan view enlargement of one site 13 with one BGA/CSPdevice 11 embedded.

FIG. 2 shows an exploded perspective view of the BGA probe handler ofthe present invention.

Identified within the BGA probe handler are the following sub-sections;20 is the docking plate, 22 is the device strip heater table, 24 are theopenings to mount the camera and laser sensors, 26 is the tower lamp, 28is the top door for access to the device strip carrier cassette (thiscassette serves to store and handle the device strip carriers and willbe explained under FIG. 5 following; see also the following paragraph),30 is the touch screen for human operator control, 32 is the operatorcontrol panel and 34 is the loading and unloading door for the devicestrip carrier cassette. The heater table 22 will be further highlightedwithin the scope of the present invention.

The cassette used during the operation of the BGA probe handler servesas a mechanical means for storing a multiplicity of BGA device stripcarriers, BGA device strips are mounted onto the BGA device stripcarrier 14 (FIG. 1a). The cassette as a unit is inserted into the BGAdevice probe handler. The device strip carrier 14 (FIG. 1a) is insertedinto or removed from the cassette, this insertion into or removal fromthe cassette is performed by the device strip carrier loader/unloaderarm and typically takes place before or after BGA/CSP device testing.

Docking plate 20 serves to mate the device strip carrier 14 (FIG. 1a)with the heater table 22 that is positioned on top of and forms part ofthe device handler apparatus.

The heater table 22 serves to control the temperature of the devicestrip 12 (FIG. 1a) that is mounted in the BGA device probe handler andas such enables device testing under extreme conditions of temperature.

The camera and laser sensors are mounted into the BGA probe handler viaopenings 24. The laser sensor senses the thickness of the BGA devicestrip 12 (FIG. 1a) and provides data that allow for thickness (of theBGA device strip 12) compensation and, as a consequence, for the exactpositioning of the tester probe. There are two cameras provided with theprobe handler. One camera monitors the position of the BGA device strip12 (FIG. 1a) and aligns the device strip for proper position within theprobe handler. The second camera monitors the pins of the tester probeand assures alignment of the tester probe pins with the BGA devicestrip.

The tower lamp 26 performs the conventional function of drawingattention to the BGA probe handler if unusual conditions are detectedrelated to the probe handler or any other operational condition ofenvironment or control related to the BGA device strip. The tower lamp26 is, in other words, a means whereby the equipment, in this case theBGA probe handler, draws the attention of a human operator.

The touch screen 30 combined with the operator control panel 32 providethe means by which the human operator of the BGA probe handler controlsand directs functions related to the operation of the BGA probe handler.These functions can include BGA device loading into the BGA probehandler, removing of the BGA device from the BGA probe handler,adjusting BGA device strip temperature possibly together with the timeduration during which the BGA device is exposed to a given temperature,human operator interfacing with and control of probe handler cameraand/or laser functions, releasing or opening of the cassette loading andunloading doors, and others.

The top door 28 provides access to the BGA device cassette once thiscassette has been positioned within the BGA device handler.

The BGA device strip carrier cassette loading/unloading door 34 servesas the point of entry or exit of the BGA device strip carrier cassetteinto and from the BGA probe handler apparatus. Door 34 can, the same asdoor 28, be manually operated by the operator of the BGA probe handler.

FIG. 3 shows an exploded perspective view of the heater table of the BGAprobe handler. Specifically highlighted are the BGA device strip carrierguides 35, the BGA device strip carrier orientation pins 36 and thevacuum ports 37. The BGA device strip carrier guides 35 (four in total,mounted as shown at equal intervals around the periphery of the heatertable) serve to position the BGA device strip carrier 14 (FIG. 1a) onwhich the BGA device strip 12 (FIG. 1a) is mounted into the heatertable. Vacuum ports 37 allow for vacuum suck to keep the BGA devicestrip carrier 14 (FIG. 1a) in place during the time that the BGA devicestrip carrier 14 (FIG. 1a) is mounted in the probe handler table. BGAdevice strip carrier orientation pins 36 further facilitate theinsertion of the BGA device strip carrier 14 (FIG. 1a) into the heatertable. Opposing and matching cutouts have been provided for this purposein the circumferences of the BGA device strip carrier 14 (see 17, FIG.1a).

FIG. 4 shows an exploded perspective view of the probe handler. Thevarious components within this probe handler are as follows:

73 provides a diagram that defines the X and Y direction as used withinFIG. 4, it is understood that the Z-direction is the direction that isperpendicular to the indicated X-Y plane,

41 is a double action pneumatic cylinder for movement of ink marker 42,

42 is an ink marker used as part of the probe handling procedure,

43 is an ink marker slide, used as part of the probe handling procedure,this ink marker slide moves the ink marker in the Y-direction,

44 is camera #1, this camera is used to record and control the positionof the BGA device strip and aligns the BGA device strip within the probehandler apparatus,

45 is the proximity sensor, this sensor determines the BGA device stripthickness and as such provides data that allow for variation in thisthickness. This variation in BGA device strip thickness requires thatthe position of the test probe is adjusted in order to make propercontact with the BGA device strip,

46 is the camera slide that allows movement of camera #1 (44) thatrecords and controls the position of the BGA device strip within theprobe handler,

47 is the probe handler table, this table is equipped with (not shown) aheater and vacuum suction and must, during BGA device strip testing, bepositioned in the appropriate Z-height position to make contact withprobes,

48 is the camera #2, this camera monitors the tester probe pins and inso doing assures proper alignment between these tester probe pins andthe BGA device strip,

49 is the stepper motor with encoder, used for theta position/alignmentof the strip,

50 is the vacuum suction applied to keep the BGA device strip carrier 14(FIG. 1a) in place once it is placed on device carrier transfer arm 51,

51 is the device strip carrier transfer arm which is used to transferthe BGA device strip carrier between the BGA device strop carrier inputor loading position (the BGA device strip carrier input/output magazineor cassette) and the testing/heater table position and visa versa,

52 is a servo motor for the BGA device strip carrier transfer arm 51,this servo motor actuates the rotation 57 of the BGA device stripcarrier transfer arm 51,

53 is a grip finger, grip finger 53 takes possession of or clamps theBGA device strip carrier after the BGA device strip carrier has beenmoved by the BGA device strip carrier loading/unloading arm from thedevice input/output magazine/cassette 60/61 to the position of the BGAdevice strip carrier transfer arm 57, the grip finger 53 holds the BGAdevice strip carrier during the process of physical transfer of the BGAdevice strip carrier to and from the BGA device strip carrier transferarm 51,

54 is the servo motor for the BGA device strip carrier loading/unloadingarm 74, this servo motor actuates the BGA device strip carrierloading/unloading arm 74 in the Y direction,

55 is the device strip carrier slide for the BGA device strip carrierloading/unloading arm 74, the BGA device strip carrier loading/unloadingarm 74 can move in the Z-direction and, in so doing, access differentBGA device strip carriers stored at different levels or heights withinthe BGA device strip carrier input or output magazines 60 and 61respectively,

56 is a servo motor, this servo motor actuates the BGA device stripcarrier loading/unloading arm 74 in the Z-direction,

57 is the rotation in which the BGA device strip carrier transfer arm 51can be turned, this rotation 57 transfers the BGA device strip carrierfrom the input position to the heater table position and visa versa,

58 is the motion of the BGA device strip carrier loading/unloading arm74 in the Z-direction,

59 are two magazine sensors that indicate the position of the input andoutput magazine 60 and 61 respectively with respect to a home or trueposition, this home or true position must be true with respect to theposition of the BGA device strip carrier loading/unloading arm 74,

60 is the input magazine, BGA device strip carriers that contain BGAdevice strips that are to be tested are entered into the probe handlerapparatus via this magazine,

61 is the output magazine, BGA device strip carriers that contain BGAdevice strips that have been tested exit the probe handler apparatus viathis magazine,

62 is the servo motor the actuates the X-table 63,

63 is the X-table, that is the table that can position the proberhandler table 47 in the X-direction,

64 is a servo motor, this servo motor moves the heater table/chuck 47 inthe Z-direction (up/down direction),

65 is the servo motor the actuates the Y-table 65,

66 is the Y-table, that is the table that can position the proberhandler table 47 in the Y-direction,

70 is a pneumatic double action cylinder that can actuate movement 73 ofthe carrier slide 46,

71 is the direction that the ink marker 43 can move,

72 is the rotational direction of prober handler table 47,

73 is a diagram that indicates the X and Y direction as defined for theexploded perspective view of the probe handler, FIG. 4

74 is the BGA device strip carrier loading/unloading arm,

75 indicates the Y-direction in which the BGA device striploading/unloading arm 74 can travel.

The function of the heater table/main chuck is to hold and heat the BGAdevice strip carrier for elevated temperature testing. During actualtesting, the heater table/main chuck steps from device to device whilemaking contact with the probe card and the pogo pins. The heatertable/main chuck can move in the X, Y, and Z direction and has, inaddition, rotational freedom of movement.

FIG. 5 shows an exploded view of the BGA probe handler. Shown in FIG. 5are:

80 is the X-Y table,

81 is the main chuck/heater table,

82 is the BGA device strip carrier transfer arm, this arm has beenhighlighted under 51, FIG. 4,

83 is the BGA device strip carrier loading/unloading arm, this arm hasbeen highlighted under 74, FIG. 4,

84 is the BGA device strip carrier cassette,

85 is the storage location for the BGA device strip carrier for untestedparts, this magazine has been highlighted under 60, the input magazine,FIG. 4,

86 is the storage location for the BGA device strip carrier for testedparts, this magazine has been highlighted under 61, the output magazine,FIG. 4,

87 is the probe handler base plate.

The function of the BGA device strip carrier cassette 84 is to hold thetested and untested BGA device strip carriers.

The function of the BGA device strip carrier loading/unloading arm 83 isto move BGA device strip carriers between the cassette and theloading/unloading transfer arm 82. The loading/unloading arm 83 can movein the X and Z direction (see diagram 88), this has been highlightedabove as the function of item 74, FIG. 4.

The function of the BGA device strip carrier transfer arm is to lift BGAdevice strip carriers from the loading/unloading arm and place the BGAdevice strip carriers on the heater table/main chuck for probing. Afterprobing is complete the BGA device strip carrier transfer arm will liftthe BGA device strip carriers from the heater table and place the BGAdevice strip carriers onto the BGA device strip carrierloading/unloading arm.

FIG. 6a and FIG. 6b show two types of probe pins that can be used forBGA/CSP device testing. These probe pins within the scope of the presentinvention must meet the following requirements:

1) be able to contact a contacting surface that comprises a sphericalsolder ball and also a flat surface.

2) accommodate a contacting or ball pitch, which varies from 1 mm. to500 um.

3) accommodate a solder ball surface planarity of 100 microns.

4) vary in number from 4 to 64 to accommodate device packages that varyfrom 2×2 to 8×8 devices.

5) the location of the probes must be such that the contact balls in anymatrix form that exists across the BGA/CSP device can be contacted.

In selecting the probe pins which can be used within the scope of thepresent invention the following types of pins can be considered:

1) vertical pogo pin, shown in FIG. 6a

2) cobra pin, shown in FIG. 6b

3) membrane pin, not shown.

These types of pins are known within the state of the art ofsemiconductor device testing and are not part of the present invention.

FIGS. 7a, 7 b and 7 c show how BGA/CSP devices will be tested within thescope of the present invention, that is using the device-probing conceptcombined with the BGA/CSP device strip carrier concept.

FIG. 7a shows how the device strip carrier 71 is stored and moved withthe help of the device strip carrier cassette 80. The device stripcarrier 71 is loaded into and unloaded from the device strip carriercassette 80 using the loader/unloader arm 74. At the time that the BGAdevice strip carrier 71 has to be loaded onto the probe handler theloader/unloader arm 74 removes the strip carrier 71 from the stripcarrier cassette 80 as shown in FIG. 7a.

FIG. 7b shows how the transfer arm 72 is used to lift the device stripcarrier 71 from the loader/unloader arm 74 (FIG. 7a) onto the topsurface 90 of the main chuck and the heater table with the motion 92.

The final assembly for testing the BGA/CSP device is shown in FIG. 7cwhere the device strip carrier 71 is positioned on the top surface ofthe main chuck/heater table 90 which is positioned on a chuck supporttable 106. The probe card 102 is attached to the test head 104. Afterlowering the probe card 102 onto the BGA/CSP device that is containedwithin the device strip carrier 71, the testing of the BGA/CSP devicecan take place.

FIG. 8 shows further details of the construction of the probes used totest the BGA devices contained within the BGA device strip of thepresent invention.

FIG. 8a shows probes 82 that contact the balls 84 of the BGA device thatis contained within the BGA package 86. Probes 82 approach the deviceballs under an angle, spring contact is in this manner establishedbetween the tester probes and the contact balls of the BGA device.

FIG. 8b shows another approach in the construction of the test probes.Probes 88 approach the contact balls of the BGA device in a directionthat is perpendicular to the plane of the contact balls, probes 88 canbe hollow in design whereby inside the body of the probe a spring (notshown) can be mounted that urges the head of the probe toward the balls84 of the BGA device. The plane 90 represents a means of mounting thetest probes and can, for instance, be a printed circuit board whereinfurther wiring is provided that forms part of the testing circuitry forthe BGA devices under test.

FIG. 8c shows yet another approach to the construction of the testprobes. A BGA device strip carrier 92 contains the BGA device that is tobe tested (not shown). A docking plate 98 holds a prober card 96 intowhich the test probes 94 are mounted. The BGA device strip carrier isshown as being positioned on top of the heater table 100.

While the present invention has been shown and described with referenceto the preferred embodiment thereof, it will be understood by thoseskilled in the art of semiconductor testing that the foregoing and otherchanges may be made therein without departing from the spirit and scopeof the present invention.

What is claimed is:
 1. A Ball Grid Array measurement apparatus fortesting Ball Grid Array devices, said measurement apparatus containing atest head, comprising: a base or main chuck; an assemblage of ball gridarray devices contained within a device strip carrier; fixture means,connected to the base, for holding the ball grid array device stripcarrier; actuating means connected to the base, for moving the base inat least one axis in response to a motion control signal; positionsensing means, connected to the base, for sensing a position of thebase, wherein the position sensing means has a position output; touchsensor means, connected to the base, for sensing contact with the ballgrid array when the actuating means moves the base toward the ball gridarray, wherein the touch contact means further comprises a plurality ofgas pressure backed contact switches, each in a predetermined position,and each having a contact signal; computer sensor means, connected toreceive the contact signal; and the position signal, for storing theposition of the base at a time of contact to perform electricalmeasurements of the ball grid array after the ball grid array device hasbeen placed in the measurement position with respect to the test head.2. The apparatus of claim 1 wherein said assemblage of ball grid arraydevices contained within a device strip carrier is a multiplicity ofball grid array devices mounted in a device strip carrier wherein saiddevice strip carrier contains one or more device strips said devicestrips to have a first and a second dimension said device strips furtherto be contained within one plane whereby said first dimension of saiddevice strips exceeds said second dimension of said device strips in adirection that is perpendicular to said first dimension by aconsiderable amount said device strips to contain a multiplicity of BGAdevice sites said BGA device sites to be arranged within said plane ofsaid device strip and furthermore arranged along said first dimension ofsaid device strip said BGA device sites to contain a multiplicity of BGAdevices said BGA devices to be arranged within the plane of said devicesites furthermore arranged along said first and second dimension of saiddevice strip.
 3. The apparatus of claim 1 wherein actuating means,connected to the base, are provided for moving the base in two mutuallyperpendicular directions in response to motion control signals.
 4. Theapparatus of claim 1 wherein said moving of said base moves the positionof said BGA device with respect to said test head from CSP device to BGAdevice within a device strip carrier.
 5. The apparatus of claim 1wherein said moving of said base moves the position of said BGA devicewith respect to said test head from BGA device to BGA device within amultiplicity of device strip carriers.
 6. The apparatus of claim 1wherein said moving of said base moves the position of said BGA devicewith respect to the test head from BGA site to BGA site within a devicestrip carrier.
 7. The apparatus of claim 1 wherein said moving of saidbase moves the position of said BGA device with respect to the test headfrom BGA site to BGA site within a multiplicity of device stripcarriers.
 8. A Chip Scale measurement apparatus for testing Chip ScalePackaging (CSP) devices, said apparatus containing a measurement testhead, comprising: a base or main chuck; an assemblage of CSP devicescontained within a device strip carrier; fixture means, connected to thebase, for holding the CSP device strip carrier; actuating meansconnected to the base, for moving the base in at least one axis inresponse to a motion control signal; position sensing means, connectedto the base, for sensing a position of the base, wherein the positionsensing means has a position output; touch sensor means, connected tothe base, for sensing contact with the CSP device when the actuatingmeans moves the base toward the CSP device, wherein the touch contactmeans further comprises a plurality of gas pressure backed contactswitches, each in a predetermined position, and each having a contactsignal; computer sensor means, connected to receive the contact signal;and the position signal, for storing the position of the base at a timeof contact to perform electrical measurements of the CSP device afterthe CSP device has been placed in the measurement position with respectto the test head.
 9. The apparatus of claim 8 wherein said assemblage ofCSP devices contained within a device strip carrier is a multiplicity ofCSP devices mounted in a device strip carrier wherein said device stripcarrier contains one or more device strips said device strips to have afirst and a second dimension said device strips further to be containedwithin one plane whereby said first dimension of said device stripsexceeds said second dimension of said device strips in a direction thatis perpendicular to said first dimension by a considerable amount saiddevice strips to contain a multiplicity of CSP device sites said BGAdevice sites to be arranged within said plane of said device strip andfurthermore arranged along said first dimension of said device stripsaid BGA device sites to contain a multiplicity of BGA devices said BGAdevices to be arranged within the plane of said device sites furthermorearranged along said first and second dimension of said device strip. 10.The apparatus of claim 8 wherein actuating means, connected to the base,are provided for moving the base in two mutually perpendiculardirections in response to motion control signals.
 11. The apparatus ofclaim 8 wherein said moving of said base moves the position of said CSPdevice with respect to the test head from CSP device to CSP devicewithin a device strip carrier.
 12. The apparatus of claim 8 wherein saidmoving of said base moves the position of said CSP device with respectto the test head from CSP device to CSP device within a multiplicity ofdevice strip carriers.
 13. The apparatus of claim 8 wherein said movingof said base moves the position of said CSP device with respect to thetest head from CSP site to CSP site within a device strip carrier. 14.The apparatus of claim 8 wherein said moving of said base moves theposition of said CSP device with respect to the test head from CSP siteto CSP site within a multiplicity of device strip carriers.